• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.7
• /
• pp.1152-1161
• /
• 1999

Buffalo raising to produce milk, meat, and draught power as well as other products continues to be important in Asia and other parts of the world in the next century due to an increase in the demand for such products and the unique roles of buffaloes in rural economy. Long-term breeding strategies with special relevance to present and future farming systems prevailing in developing countries are proposed. Some important considerations in the choice of certain breeding strategies for long-term genetic improvement in buffaloes are discussed. Some recent research results in genetic selection and crossbreeding of buffaloes are highlighted. A review of genetic inheritance of buffalo traits is presented as well as a discussion Of certain quality traits of buffaloes which deserve future research for improvement.

• Korean Journal of Poultry Science
• /
• v.22 no.1
• /
• pp.15-31
• /
• 1995

This study was carried out to develop a computer software system for poultry breeding by using microcomputer(PC). Through this study, SPPB(Statistical Package for Poultry Breeding) was designed and developed, which can help poultry breeder collect and analyse the chick records. A main feature of the system was the application of user-oriented procedure, for example, choice of the flock file, selection of the family size and the desired traits. Creation of the data files and the breeding files. calculation of the elementary statistics, estimation of the heritability and the genetic and phenotypic correlation coefficients can be obtained by user's choice of the sire and dam family size. Also, it is possible to estimate the various selection indices through this system. Easiness of using this system and the flexibility of the file management could help increasing the efficiency of related practical poultry breeding jobs. Correctness and relationships between the unit programs in the system were proved through the run-test of the SPPB using sample data. Because it wasn't able to collect breeding records at the commercial breeding farm, effectiveness of the system was not proved totally. Also. it will be necessary to develop the integrated software system which make possible to computerize the general works at breeding farm and the genetic analyses of the records from chick breeders.

• Korean Journal of Breeding Science
• /
• v.43 no.2
• /
• pp.103-114
• /
• 2011

In recent years, genomic resources and information have accumulated at an ever increasing pace, in many plant species, through whole genome sequencing, large scale analysis of transcriptomes, DNA markers and functional studies of individual genes. Well-characterized species within key plant taxa, co-called "model systems", have played a pivotal role in nucleating the accumulation of genomic information and databases, thereby providing the basis for comparative genomic studies. In addition, recent advances to "Next Generation" sequencing technologies have propelled a new wave of genomics, enabling rapid, low cost analysis of numerous genomes, and the accumulation of genetic diversity data for large numbers of accessions within individual species. The resulting wealth of genomic information provides an opportunity to discern evolutionary processes that have impacted genome structure and the function of genes, using the tools of comparative analysis. Comparative genomics provides a platform to translate information from model species to crops, and to relate knowledge of genome function among crop species. Ultimately, the resulting knowledge will accelerate the development of more efficient breeding strategies through the identification of trait-associated orthologous genes and next generation functional gene-based markers.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.31-31
• /
• 2022

Rice contains a wealth of genetic diversity, both within Oryza sativa and in related A-genome species. Decades of genetic research into this diversity have identified dozens of major genes contributing to a wide variety of important traits, including disease resistance, abiotic stress tolerance (drought, salinity, submergence, heat, cold etc.), grain quality, flowering date and maturity and plant architecture. Yet despite these opportunities, very few of the major genes and QTLs known have been successfully applied through rice breeding programs to produce sustained changes in farmer's fields. This presentation will briefly examine some of the factors limiting application of major genes in the mainstream breeding programs, and steps that have been taken to alleviate those limitations. As a result of these interventions, dozens of major genes that were previously unavailable to breeders are now being used confidently in the variety development process. Case studies will be discussed of genes critical for blast resistance worldwide, rice yellow mottle virus for Africa, and new validated QTLs for salinity tolerance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.9
• /
• pp.1226-1234
• /
• 2015

The development of effective genetic evaluations and selection of sires requires accurate estimates of genetic parameters for all economically important traits in the breeding goal. The main objective of this study was to assess the relative performance of the traditional lactation average model (LAM) against the random regression test-day model (RRM) in the estimation of genetic parameters and prediction of breeding values for Holstein Friesian herds in Ethiopia. The data used consisted of 6,500 test-day (TD) records from 800 first-lactation Holstein Friesian cows that calved between 1997 and 2013. Co-variance components were estimated using the average information restricted maximum likelihood method under single trait animal model. The estimate of heritability for first-lactation milk yield was 0.30 from LAM whilst estimates from the RRM model ranged from 0.17 to 0.29 for the different stages of lactation. Genetic correlations between different TDs in first-lactation Holstein Friesian ranged from 0.37 to 0.99. The observed genetic correlation was less than unity between milk yields at different TDs, which indicated that the assumption of LAM may not be optimal for accurate evaluation of the genetic merit of animals. A close look at estimated breeding values from both models showed that RRM had higher standard deviation compared to LAM indicating that the TD model makes efficient utilization of TD information. Correlations of breeding values between models ranged from 0.90 to 0.96 for different group of sires and cows and marked re-rankings were observed in top sires and cows in moving from the traditional LAM to RRM evaluations.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.12
• /
• pp.1871-1880
• /
• 2018

Objective: Recently, there has been an increasing interest in conservation of native genetic resources of chicken on a worldwide basis. Most of the native chicken breeds are threatened by extinction or crossing with ecotypes. Methods: Six Saudi native chicken breeds including black naked neck, brown frizzled, black, black barred, brown and gray were used in the current study. The aim of the current study was to evaluate genetic diversity, relationship and population structure of Saudi native chicken breeds based on 20 microsatellite markers. Results: A total of 172 alleles were detected in Saudi native chicken breeds across all 20 microsatellite loci. The mean number of alleles per breed ranged from 4.35 in gray breed to 5.45 in normally feathered black with an average of 8.6 alleles. All breeds were characterized by a high degree of genetic diversity, with the lowest heterozygosity found in the brown breed (72%) and the greatest in the frizzled and black barred populations (78%). Higher estimate of expected heterozygosity (0.68) was found in both black breeds (normal and naked neck) compared to the other chicken populations. All studied breeds showed no inbreeding within breed (negative inbreeding coefficient [$F_{IS}$]). The phylogenetic relationships of chickens were examined using neighbor-joining trees constructed at the level of breeds and individual samples. The neighbor-joining tree constructed at breed level revealed three main clusters, with naked neck and gray breeds in one cluster, and brown and frizzled in the second cluster leaving black barred in a separate one. Conclusion: It could be concluded that the genetic information derived from the current study can be used as a guide for genetic improvement and conservation in further breeding programs. Our findings indicate that the Saudi native chicken populations have a rich genetic diversity and show a high polymorphism.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.42 no.6
• /
• pp.600-603
• /
• 2009

Genetic and phenotypic parameter estimates for measurement traits were obtained from pacific oyster Crassostrea gigas at nine months old. For the growth-related traits among nine months old pacific oyster, heritabilities of shell length, shell height, shell width, total weight, body weight and shell weight were estimated as 0.4855, 0.5248, 0.0884, 0.7236, 0.7726 and 0.6957, respectively. Genetic correlations among the growth-related traits of pacific oyster at nines month old, shell length, shell height, shell width, total weight, body weight, shell weight were showing highly positive correlations. Breeding value on growth-related traits of pacific oyster at nine months old were estimated as shell length -7.044-11.870, shell height -11.380-18.370, shell width -1.234-2.831, total weight -8.339-17.140, body weight -1.813-3.507 and shell weight -4.422-8.837. The results show that there is quite substantial additive genetic variance for measurement traits in pacific oyster that can be exploited through selective breeding.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.04a
• /
• pp.61-61
• /
• 2019

In any crop breeding program Selection and use of genetically diverse genotypes to develop cultivars with a broad genetic base is important. Molecular markers play a major role in selecting diverse genotypes. Molecular breeding programs of the crop can be made more efficient by use of molecular markers. The present study was done with an aim of analyzing genetic diversity and the population structure in 24 accessions of sunflower (Helianthus annus L.) from Kenya genetic diversity using 35 EST-SSR and gSSR primers.Out of the 35 markers 3 were not polymorphic as they indicated Polymorphic Information content( PIC) of value 0.00 and so the data analysis was done using 32 markers . The 32 set of markers used produced 29 alleles ranging from 2 to 7with a mean of 3.0 alleles per locus.The average value of polymorphic information contents(PIC) were 0.3 .Genetic diversity analysis using these markers revealed 3 major clusters. This result could be useful for designing strategies to make elite hybrid and inbreeding of crossing block for breeding and future molecular breeding programs to make elite variety.

• Journal of Animal Science and Technology
• /
• v.62 no.6
• /
• pp.790-800
• /
• 2020

The Yeonsan Ogye (YO) chicken is a natural heritage of Korea, characterized by black feathers, skin, bones, eyes, and comb. The purebred of YO population has been reared under the natural mating system with no systematic selection and breeding plan. The purpose of this study was to identify the genetic diversity and find the optimal number of population sub-division using 12 polymorphic microsatellite (MS) markers to construct a pedigree-based breeding plan for the YO population. A total of 509 YO birds were used for this study. Genetic diversity and population structure analysis were conducted based on the MS marker genotype information. The overall average polymorphic information content value and expected heterozygosity of the population were 0.586, and 0.642, respectively. The K-mean cluster analysis based on the genetic distance result confirmed that the current YO population can be divided into three ancestry groups. Individuals in each group were evaluated based on their genetic distance to identify the potential candidates for a future breeding plan. This study concludes that a future breeding plan with known pedigree information of selected founder animals, which holds high genetic diversity, could be the best strategy to ensure the conservation of the Korean YO chicken population.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.6
• /
• pp.974-981
• /
• 2021

The aim of this study was to evaluate genetic parameters of growth traits for improving selective breeding in olive flounder Paralichthys olivaceus produced in April 2019. The total length and body weight at 11-, 18-, and 22-months-old were measured for 7,479, 2,831 and 1,904 individuals, respectively. Since 2004, we have been conducting a selective breeding program to improve growth traits in the olive flounder. Data were analyzed using the restricted maximum likelihood method using the multiple traits animal model. The effect of sex and production period showed significant differences in all traits (P<0.05). The heritability of all traits was 0.428-0.520, which is relatively high by measurement month. Therefore, it is considered that individual selection will be more advantageous than family selection. However, to maintain an appropriate degree of inbreeding and genetic diversity for future generations, it is necessary to consider family selection adequately. Results of the correlation analysis between the same traits according to the measurement period indicated that considering production costs such as feed cost, selection at 18-months-old will be advantageous. Olive flounder is a major aquaculture species in Korea, and continuous selective breeding research is essential to improve productivity.